Method and device for detecting and correcting the angle of a prism structure multi-exit light beam

Abstract

The present disclosure relates to the technical field of optical manufacturing, and provides a method and device for detecting and correcting the included angle of multiple exit beams of a prism structure. The method comprises the steps of: emitting a detection beam towards the prism structure, obtaining at least two beams of to-be-detected exit light emitted from the prism structure; and based on the principle of laser interference, performing laser interference on the at least two beams of to-be-detected exit light respectively, and obtaining the included angle between the at least two beams of to-be-detected exit light. The technical solution of the present disclosure can improve the detection accuracy of the included angle of the light beams, thereby solving the technical problem of low detection accuracy of the included angle of the light beams in the prior art.

Description

Technical Field

[0001] This disclosure relates to the field of optical component manufacturing technology, and in particular to a method and apparatus for detecting and correcting the included angle of multiple emitted beams in a prism structure. Background Technology

[0002] In optical systems, the predetermined optical path is typically designed as a theoretical optical path. In this theoretical path, the light beam undergoes reflection and refraction without deviation, resulting in an ideal output beam. However, during the actual formation of the theoretical optical path using optical components, deviations occur due to factors such as manufacturing errors. For example, a combined deflection angle may develop in the optical path, causing the output beam to deflect at an angle, and theoretically, multiple parallel output beams may form beam angles.

[0003] The beam deflection angle refers to the change in the direction of a beam of light during its propagation due to reflection and refraction. For example, a beam of light incident from one facet of a prism undergoes two refractions and exits from the other facet of the prism. The deflection angle between the outgoing and incoming directions of the light is the deflection angle of the light after passing through the prism.

[0004] The beam angle refers to the angle between multiple beams of light that change their propagation direction due to reflection and refraction by different optical components or different positions of the same optical component during propagation. For example, multiple beams of light incident from one facet of a prism undergo two refractions and then exit from another facet of the prism. The angle between any two of these exit beams is the beam angle.

[0005] The beam angle of a cemented prism is an important indicator for evaluating its performance. Typically, a collimator or comparator can be used to measure the beam angle. However, collimators have low accuracy and cannot eliminate the influence of stray light from other beams in the testing system, limiting their application to high-precision parts. Comparators also have low accuracy and cannot directly measure the beam angle between pairs of multiple beams. Furthermore, using a comparator requires a reference plane, which introduces systematic errors into the testing system.

[0006] Improving the detection accuracy of the beam angle of a cemented prism is a technical problem that urgently needs to be solved. Summary of the Invention

[0007] In view of this, the present disclosure provides a method and apparatus for detecting and correcting the included angle of multiple emitted beams in a prism structure, in order to solve the technical problem of low detection accuracy of beam included angle in the prior art.

[0008] On the one hand, this application provides a method for detecting and correcting the angle of multiple outgoing beams from a prism structure, including the steps of: emitting a detection beam toward the prism structure to obtain at least two outgoing beams to be measured emitted from the prism structure;

[0009] Based on the principle of laser interference, laser interference is performed on at least two beams of light to be measured to obtain the beam angle between at least two beams of light to be measured.

[0010] In an optional embodiment, based on the principle of laser interference, the step of performing laser interference on at least two beams of light to be measured to obtain the beam angle between the at least two beams of light to be measured includes:

[0011] Laser interference is performed on at least two beams of outgoing light to be measured to obtain at least two corresponding interference surface patterns;

[0012] Based on the two interference surface diagrams, the beam angle between the two outgoing beams to be measured is obtained.

[0013] In an optional embodiment, in the step of obtaining the beam angle between the two outgoing beams to be measured based on at least two interference surface patterns:

[0014] Based on the two interference surface diagrams, the beam deflection angle of each beam of the outgoing light to be measured is calculated.

[0015] The beam angle between the two emitted beams is calculated based on the beam deflection angles of the two emitted beams.

[0016] In an optional embodiment, after the step of performing laser interference on at least two beams of light to be measured to obtain the beam angle between the at least two beams of light to be measured, based on the principle of laser interference, the method further includes:

[0017] The optical path difference between the two beams of light to be measured is calculated based on the angle between the beams and the direction of the deviation.

[0018] Based on the optical path difference between the two beams of light to be measured, the angle value and direction of the combined deflection angle generated by all reflection processes in the optical path of the prism structure are obtained;

[0019] The angle of the reflecting surface in the prism structure is adjusted according to the angle value and direction of the comprehensive deflection angle so that the beam angle between the two beams to be measured is less than the preset angle value.

[0020] In an optional embodiment, in the step of adjusting the angle of the reflecting surface in the prism structure according to the angle value and direction of the combined deflection angle, so that the beam angle between the two beams to be measured is less than a preset angle value:

[0021] The prism structure includes a common part and a single part for reflecting the light beam, wherein the common part is shared in the optical path of at least two light beams, and the single part is used exclusively in the optical path of each laser beam.

[0022] By correcting the reflection angle of the single-purpose unit in the optical path of the corresponding outgoing beam to be measured, the beam angle between the two outgoing beams to be measured is made less than a preset angle value; wherein the direction of the angle corrected by the single-purpose unit is opposite to the direction of the overall deflection angle, so as to cancel the angle deviation of the overall deflection angle.

[0023] In an optional embodiment, in the step of emitting a detection beam toward the prism structure and acquiring at least two beams of light to be measured emitted from the prism structure:

[0024] The prism structure includes:

[0025] The beam splitter lens group is used to split a detection laser beam into multiple first outgoing beams; one of the detection laser beams is used as the detection beam, and the first outgoing beams are used as the outgoing beams to be tested.

[0026] Or / and

[0027] The cemented lens assembly forms multiple second outgoing beams by propagating multiple detection incident beams along a predetermined optical path at different positions within the cemented lens assembly; wherein the multiple detection incident beams are detection beams, and the second outgoing beams corresponding to the multiple detection incident beams are outgoing beams to be measured.

[0028] In an optional embodiment, in the step of emitting a detection beam toward the prism structure and acquiring at least two beams of light to be measured emitted from the prism structure:

[0029] The cemented prism includes a beam splitter lens group and a cemented lens group, wherein the multiple first outgoing beams emitted from the beam splitter lens group serve as the multiple detection incident beams of the cemented lens group.

[0030] After a detection laser beam is split by a beam splitter lens group, it forms multiple first outgoing beams;

[0031] Multiple beams of first emitted light propagate along a predetermined optical path at different positions within the cemented mirror assembly and then exit separately to form multiple beams of second emitted light.

[0032] In an optional embodiment, the step of correcting the reflection angle of the single component in the optical path of the corresponding outgoing beam to be measured, so that the beam angle between the two outgoing beams to be measured is less than a preset angle value:

[0033] The beam splitter lens assembly includes:

[0034] The first polarizing beam splitter has a first incident surface and a first polarizing beam splitter surface.

[0035] At least one second prism, the second prism being connected to the first polarizing beam splitter, and having a first beam splitting surface, a second beam splitting surface, and a first light-emitting surface;

[0036] The third prism is connected to the first beam-splitting surface of the second prism and has a third beam-splitting surface and a second light-emitting surface, with the second light-emitting surface and the first light-emitting surface being arranged on the same side.

[0037] The detection laser enters from the first incident surface and is reflected by the first polarization beam splitter to form two beams. One beam penetrates the first beam splitter, enters the third prism, is reflected by the third beam splitter, and exits from the second exit surface to form a first exit beam. The other beam is reflected by the first beam splitter, then reflected again by the second beam splitter, and exits from the first exit surface to form another first exit beam.

[0038] The single-use unit includes a second beam splitter and / or a third beam splitter. By correcting the angle of the second beam splitter and / or the third beam splitter, the beam angle between the first emitted beams is made less than a preset angle value.

[0039] In an optional embodiment, the step of correcting the reflection angle of the single component in the optical path of the corresponding outgoing beam to be measured, so that the beam angle between the two outgoing beams to be measured is less than a preset angle value:

[0040] Cemented lens assembly includes:

[0041] The second polarizing beam splitter has a second entrance and exit surface, a second polarizing beam splitter surface, and a first side surface and a second side surface arranged opposite to each other.

[0042] At least two reflective combination mirrors are respectively set at different positions of the second polarizing beam splitter and are respectively set to correspond to different first outgoing beams. The reflective combination mirror includes a reflective waveplate and a corner pyramid, which are respectively set on the first side and the second side.

[0043] The first outgoing light enters the second polarizing beam splitter through the second entrance and exit surfaces, is reflected by the second polarizing beam splitter to the reflecting waveplate, is reflected by the reflecting waveplate, passes through the second polarizing beam splitter and enters the corner pyramid, is reflected by both sides of the corner pyramid and enters the reflecting waveplate, passes through the second polarizing beam splitter and enters the reflecting waveplate, is reflected by the reflecting waveplate and enters the second polarizing beam splitter, is reflected by the second polarizing beam splitter, and exits from the second entrance and exit surfaces to form the second outgoing light;

[0044] The single-use unit includes the reflecting surface of the reflective waveplate and / or the reflecting surface of the pyramid. By correcting the angle of the reflecting surface of the reflective waveplate and / or the reflecting surface of the pyramid, the beam angle between the second emitted beams is made less than a preset angle value.

[0045] On the other hand, this application also proposes a device for detecting the beam angle of a cemented prism, wherein the angle detection and correction method described above is applied. The detection device includes a laser interferometer and a data processor. The laser interferometer emits a detection beam toward the prism structure to acquire at least two beams of light to be measured emitted from the prism structure and performs laser interference on them respectively. The data processor calculates and obtains the beam angle between the at least two beams of light to be measured.

[0046] The beneficial effects of this disclosed embodiment compared with the prior art are as follows: The technical solution of this application uses laser interference to obtain the interference data of the reflected light and the emitted light when the light enters the prism structure, and obtains the beam angle between the two emitted light rays based on the interference data, thereby realizing the direct detection of the emitted beam angle between the two emitted light rays of the cemented prism, and the detection accuracy is high, so as to adjust the emitted beam angle more accurately. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 This is a schematic diagram of the structure of a glued prism provided in this embodiment;

[0049] Figure 2 This is a structural schematic diagram of a glued prism provided in this embodiment from another perspective;

[0050] Figure 3 This is a top view of a glued prism provided in this embodiment;

[0051] Figure 4 This is a front view of a glued prism provided in this embodiment;

[0052] Figure 5 This is an optical path diagram of a beam splitter lens assembly for a cemented prism provided in this embodiment.

[0053] Figure 6 This is an optical path diagram of one beam of a cemented mirror assembly of a cemented prism provided in this embodiment;

[0054] Figure 7 This is a flowchart illustrating the main steps of a method for detecting and correcting the included angle of multiple emitted beams in a prism structure, as provided in this embodiment.

[0055] Figure 8 This is a flowchart illustrating the detailed steps of a method for detecting and correcting the angle of multiple outgoing beams in a prism structure, as provided in this embodiment.

[0056] The following are the labeling elements in the figure:

[0057] 100. Beam splitter mirror assembly; 110. First polarizing beam splitter prism; 111. First incident surface; 112. First polarizing beam splitter surface; 120. Second prism; 121. First beam splitter surface; 122. First exit surface; 123. Second beam splitter surface; 130. Third prism; 131. Third beam splitter surface; 132. Second exit surface; 200. Cemented mirror assembly; 210. Second polarizing beam splitter prism; 211. Second incident and exit surface; 212. Second polarizing beam splitter surface; 213. First side surface; 214. Second side surface; 220. Reflecting combination mirror; 221. Reflecting waveplate; 222. Pyramid. Detailed Implementation

[0058] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, so as to provide a thorough understanding of the embodiments of this disclosure. However, those skilled in the art will understand that this disclosure may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this disclosure with unnecessary detail.

[0059] The following is an explanation of the terms used in the embodiments of this disclosure:

[0060] A laser interferometer is a high-precision optical measuring instrument that uses the principle of laser interference to measure the shape and quality of an object's surface. The basic principle of a laser interferometer is to split a laser beam into two beams: one serves as a reference beam, and the other strikes the surface of the object being measured. After reflection, the second beam re-intercepts the reference beam, forming interference fringes. The shape and density of the interference fringes are related to the shape and surface quality of the object. Laser interferometers can be used to measure various geometric precisions, including straightness, perpendicularity, angle, surface shape, and parallelism. The measurement accuracy of a laser interferometer is extremely high, reaching the sub-micron level.

[0061] Cemented Prisms: The cemented prisms in this embodiment can be complex optical components bonded using photosensitive adhesive bonding. Since there is no medium between the bonding surfaces of the individual components of the cemented prism, its optical performance remains unchanged. Compared to adhesive bonding, cemented prisms bonded using photosensitive adhesive bonding have higher mechanical strength, more stable performance, and can maintain this performance for decades; they also exhibit less deformation and better cold and heat resistance. Specialized photosensitive adhesive bonding methods can be used for parts whose surfaces will deform during bonding, parts that may delaminate due to their large size, parts that operate under high or low temperature conditions, or parts that operate in the short-wavelength region of optical harmonics. However, photosensitive adhesive bonding requires very high manufacturing precision for the adhesive surface.

[0062] Beam splitter: In this embodiment, the beam splitter is a beam splitter lens assembly, which is a bonded component formed by multiple beam splitting prisms. A beam of light is split into multiple beams after passing through the assembly. The beam splitting prism is an optical prism that can split a beam of light in two. Typically, a beam splitting film is coated on the surface of the optical prism, so that after passing through the coated surface, part of the incident light is transmitted and part is reflected, forming two beams of transmitted and reflected light with a certain deflection angle.

[0063] Outgoing beam angle: During propagation, light's direction changes due to reflection and refraction. The angle of deflection between the outgoing and incoming directions is called the beam angle. A beam of light incident from one facet of a prism undergoes two refractions and exits from the other facet. The angle of deflection between the outgoing and incoming directions is the beam angle after the light passes through the prism. In this embodiment, the outgoing beam angle refers to the angle of deflection between the outgoing directions of the two beams after the light beam is split by the beam splitter of the cemented prism.

[0064] The purpose of this invention is to simplify the measurement of the beam angle of a prism structure, improve the operability of beam deflection angle measurement, and directly measure the angle between each pair of outgoing beams from a cemented prism, thereby improving detection accuracy and reducing the difficulty of measuring the angle between each pair of outgoing beams from a cemented prism. The cemented prism involved in this invention is composed of thirteen single-piece optically bonded elements. An incident beam passes through a beam splitter to form three outgoing beams. Each outgoing beam undergoes refraction by multiple single-piece elements, and the parallelism between each pair of the three outgoing beams is required to be less than 15″. Therefore, the angle error of each single-piece element must be within 5″; otherwise, the angle error will be compounded by the individual component errors in the system, making it difficult to meet the required specifications. By detecting the angle between each pair of outgoing beams, the optical path with problems in the cemented prism can be deduced, thereby correcting defective cemented components and ensuring that the deflection angle of the outgoing beams in the entire optical path meets the standard. Therefore, the following embodiments are proposed:

[0065] Example 1

[0066] This embodiment provides a method for detecting and correcting the beam angle of multiple outgoing beams in a prism structure. By detecting the beam angle of the prism structure, which can be a cemented prism, the method of this embodiment detects and corrects the beam angle of the cemented prism, thereby improving the detection accuracy of the beam angle of the cemented prism and improving the product quality of the cemented prism.

[0067] like Figure 1 , Figure 2 As shown, to facilitate the description of this angle detection and correction method, a specific cemented prism is used as an example. The cemented prism mainly includes: a beam splitter lens group 100 and / or a cemented lens group 200. The beam splitter lens group 100 is used to split a detection beam. After splitting, multiple first-outgoing beams are emitted from the beam splitter lens group 100. Theoretically, the multiple first-outgoing beams are flat beams. However, in reality, due to the combined deflection angle of the internal structure of the prism, there is an angle between each pair of the multiple first-outgoing beams. To avoid the beam angle affecting the final imaging effect, it is necessary to detect and correct the beam angle to obtain multiple first-outgoing beams (beam splitter 1, beam splitter 2, and beam splitter 3) that meet the preset angle (e.g., the preset angle is 15″). The resulting multiple first-outgoing beams are basically parallel, which meets the requirements.

[0068] The cemented lens assembly 200 is also composed of multiple prisms, which mainly provide a transmission path for multiple beams of flat light, so that the multiple beams of light after splitting can propagate on a predetermined path. Therefore, it is also necessary to detect and correct the beam angle of the cemented prism. After the multiple detected incident beams propagate along the predetermined optical path at different positions in the cemented lens assembly 200, they are emitted separately to form multiple second emitted beams.

[0069] The beam splitter lens assembly 100 and the cemented lens assembly 200 can be used separately for beam angle detection and correction, or they can be used in combination for beam angle detection and correction. Specific methods for beam angle detection and correction will be explained in detail in subsequent embodiments.

[0070] like Figure 1 , Figure 2As shown, in this embodiment, the beam splitter lens group 100 and the cemented lens group 200 are combined to form a cemented prism. First, the beam splitter lens group 100 is fixed to the cemented lens group 200 after beam angle detection and correction, and then the cemented lens group 200 is subjected to beam angle detection and correction. Therefore, the multiple first outgoing beams emitted from the beam splitter lens group 100 serve as the multiple detection incident beams of the cemented lens group 200. The angle between any two beams in the multiple first outgoing beams is less than a preset angle value. Within the preset angle value, the parallelism between any two first outgoing beams is less than 15″, thus they are almost parallel. The multiple detection incident beams (first outgoing beams) of the cemented lens group 200 also enter the cemented lens group 200 in an almost parallel state. The multiple almost parallel first outgoing beams propagate along a predetermined optical path at different positions within the cemented lens group 200 and then exit to form multiple second outgoing beams. By detecting and correcting the beam angle of the cemented lens group 200, the angle between any two beams in the multiple second outgoing beams is less than the preset angle value, and the parallelism between any two second outgoing beams is less than 15″, thus they are almost parallel.

[0071] like Figure 1 , Figure 2 , Figure 4 As shown, the beam splitter lens assembly 100 of this embodiment further includes the following specific structure: a first polarizing beam splitter prism 110, at least one second prism 120, and a third prism 130. The first polarizing beam splitter prism 110 is composed of two triangular prisms. A beam-splitting film is coated on the two connected inclined surfaces of the triangular prisms to form a first polarizing beam splitting surface 112, which is inclined at 45°. The right-angled surface of the triangular prism facing outward is the first incident light surface 111. Taking the side containing the first incident light surface 111 as the front side, the structure is explained using the example of the first polarizing beam splitting surface 112 reflecting the incident light in the left-right direction. The upper and lower sides of the second prism 120 are respectively set as inclined surfaces, and beam-splitting films are respectively disposed thereon to form a first beam splitting surface 121 and a second beam splitting surface 123. The right side surface of the second prism 120 is connected to the first polarizing beam splitter prism 110, and the back side of the second prism 120 is the first emitting light surface 122. The third prism 130 is connected to the first beam-splitting surface 121 of the second prism 120, and has a third beam-splitting surface 131 and a second light-emitting surface 132. The second light-emitting surface 132 is disposed on the same side as the first light-emitting surface 122. In the specific structure, the third prism 130 is connected to the left side of the second prism 120. The left and right sides of the third prism 130 are inclined and a beam-splitting film is disposed on the inclined surface on the left side to form the third beam-splitting surface 131. The back side of the third prism 130 forms the second light-emitting surface 132.

[0072] like Figure 1 , Figure 5As shown, the detection laser (incident light) enters from the first incident surface 111 and is reflected by the first polarization beam splitter 112. It is then split by the first beam splitter 121 to form two beams. One beam penetrates the first beam splitter 121 and enters the third prism 130. It is reflected by the third beam splitter 131 and exits from the second exit surface 132 to form a first exit beam (beam split 1). The other beam is reflected by the first beam splitter 121 and then reflected again by the second beam splitter 123 to exit from the first exit surface 122, forming another first exit beam (beam split 2).

[0073] like Figure 1 , Figure 5 As shown, if multiple second prisms 120 are provided, they are connected sequentially in the second direction, and the first light-emitting surface 122 of each second prism 120 can emit a first emitted light beam. For example, in this embodiment, two second prisms 120 are provided, with the second second prism 120 connected to the inclined surface where the second beam-splitting surface 123 is located below the first second prism 120. The light transmitted through the second beam-splitting surface 123 enters the beam-splitting surface below the second second prism 120, and is reflected by the beam-splitting surface to its corresponding light-emitting surface, forming a third first emitted light beam (beam splitting 3).

[0074] As can be seen from the optical path, the prism structure includes multiple beam-splitting and reflecting surfaces that reflect the light beam. These beam-splitting and reflecting surfaces are divided into shared sections and single-use sections according to their function in the optical path. The shared sections are used in the optical path paths of at least two beams, such as the first polarizing beam-splitting surface 112. The single-use sections are used exclusively in the optical path path of each laser beam; for example, in this beam splitter lens assembly 100, the single-use sections include the second beam-splitting surface 123 and / or the third beam-splitting surface 131. When performing angle correction, the shared sections and single-use sections have different functions. When the angle of the shared section of the two first emitted beams is corrected, the self-deflection angle of the two first emitted beams changes synchronously. Since the change in the self-deflection angle between the two beams is the same, the beam angle between them remains basically unchanged. However, when the angle of the single-use section of a certain first emitted beam is corrected, the beam angle between that first emitted beam and other first emitted beams is changed, achieving the technical effect of this solution. Therefore, by correcting the angle of the second beam splitter 123 and / or the third beam splitter 131, the beam angle between the emitted beams can be changed.

[0075] like Figure 1 , Figure 2 , Figure 3 , Figure 4As shown, the cemented lens assembly 200 of this embodiment further includes: a second polarizing beam splitter prism 210 and at least two reflecting combination mirrors 220. The second polarizing beam splitter prism 210 of this embodiment is disposed on the back side of the beam splitter lens assembly 100 and has a second entrance / exit surface 211, a second polarizing beam splitter surface 212, and a first side surface 213 and a second side surface 214 disposed opposite to each other. The side of the second polarizing beam splitter prism 210 facing the beam splitter lens assembly 100 is the front side, the front side is the second entrance / exit surface 211, the second polarizing beam splitter surface 212 is inclined at 45°, the first side surface 213 is the right side surface, and the second side surface 214 is the left side surface. The reflective combination mirrors 220 are respectively set at different positions of the second polarizing beam splitter 210 and are respectively set to correspond to different first emitted beams. Therefore, multiple reflective combination mirrors 220 are set according to the number of first emitted beams and are arranged in the vertical direction. The placement of the reflective combination mirrors 220 at the corresponding positions is also different depending on the position of the first emitted beam emitted by the second prism 120 and the third prism 130.

[0076] The reflective combination mirror 220 includes a reflective waveplate 221 and a corner pyramid 222, which are respectively disposed on the first side surface 213 and the second side surface 214. In the specific structure, since the first emitted light emitted from the third prism 130 and the first emitted light emitted from the plurality of second prisms 120 are staggered in the left-right direction, the two reflective cone surfaces of the corner pyramid 222 corresponding to the third prism 130 are located in the vertical direction, while the two reflective cone surfaces of the corner pyramid 222 in the plurality of reflective combination mirrors 220 corresponding to the plurality of second prisms 120 are located in the left-right direction.

[0077] like Figure 1 , Figure 2 , Figure 6 As shown, the first outgoing light enters the second polarizing beam splitter 210 through the second entrance / exit surface 211, is reflected by the second polarizing beam splitter 212 to the reflecting waveplate 221, is reflected by the reflecting waveplate 221, passes through the second polarizing beam splitter 212 and enters the corner pyramid 222, is reflected by the corner pyramid 222 on both sides and enters the second polarizing beam splitter 212 and enters the reflecting waveplate 221, is reflected by the reflecting waveplate 221 and enters the second polarizing beam splitter 210, is reflected by the second polarizing beam splitter 212, and exits from the second entrance / exit surface 211 to form the second outgoing light.

[0078] Therefore, it can be seen from the optical path principle of the cemented mirror assembly 200 that the single-use part includes the reflecting surface of the reflecting wave plate 221 and / or the reflecting surface of the pyramid 222. By correcting the angle of the reflecting surface of the reflecting wave plate 221 and / or the reflecting surface of the pyramid 222, the beam angle between the second emitted light is changed.

[0079] This application provides a method for detecting and correcting the angle between multiple outgoing beams of a prism structure. The method is used to detect and correct the angle between pairs of outgoing beams from a prism structure. The prism structure can be a cemented prism structure consisting of a beam splitter mirror group or / and a cemented mirror group, as described in Embodiment 1.

[0080] like Figure 7 As shown, this included angle detection and correction method mainly includes the following steps:

[0081] Step S100: Emit a detection beam toward the prism structure to acquire at least two beams of light to be tested emitted from the prism structure.

[0082] In the specific process, if the prism structure is the beam splitter lens group mentioned above, then the detection beam is a detection laser beam, and the multiple beams of output light to be tested are multiple first output light beams, with the first output light being the output light to be tested.

[0083] If the prism structure is the aforementioned cemented lens assembly, the detection beam is a multi-beam detection incident beam, and the outgoing light to be measured is a multi-beam second outgoing light corresponding to the multi-beam detection incident beam.

[0084] The structure is illustrated by applying this angle detection and correction method to a cemented prism that combines a beam splitter lens group and a cemented lens group. In this case, a detection laser beam is split by the beam splitter lens group to form multiple first outgoing beams. These multiple first outgoing beams then enter the cemented lens group as multiple detection incident beams and emit multiple second outgoing beams.

[0085] Step S200: Based on the principle of laser interference, perform laser interference on at least two beams of light to be measured to obtain the beam angle between at least two beams of light to be measured.

[0086] In practice, the principle of laser interference is used, and the beam angle between pairs of multiple parallel beams can be detected through calculation. The accuracy of parallelism detection using the principle of laser interference can reach within 1″, and it can avoid mutual interference between multiple beams. The method of measuring parallelism using only the principle of laser interference can directly detect the beam deflection angle between pairs of multiple parallel outgoing beams in a cemented prism, which is simple and convenient.

[0087] Therefore, the above steps simplify the beam angle detection scheme of the prism structure, improve the operability of beam angle detection between the emitted beams to be measured, and can directly measure the beam angle between each pair of multiple emitted beams of the cemented prism, thereby improving detection accuracy and reducing the difficulty of detecting the angle between each pair of multiple emitted beams of the cemented prism.

[0088] like Figure 7 , Figure 8As shown, step S200 further includes the following steps:

[0089] Step S210: Perform laser interference on at least two beams of light to be measured to obtain at least two corresponding interference surface patterns.

[0090] Step S220: Based on the two interference surface diagrams, obtain the beam angle between the two outgoing beams to be measured.

[0091] In practice, the basic principle of laser interferometry is that when the laser emitted by the laser emitter passes through a standard mirror, part of it is reflected back to the receiver to form a reference beam, while the other part is transmitted, passes through the part under test, and returns to the receiver. The two beams thus form interference fringes (interference surface pattern). The shape and density of the interference fringes (interference surface pattern) are related to the shape and surface quality of the object being measured. The interference fringes (interference surface pattern) reflect the optical path difference after the light passes through the part, and this optical path difference is related to the angle of the part. Therefore, the deflection angle of the light passing through the part can be accurately detected using the principle of laser interferometry. Furthermore, laser interferometry on different beams of light to be measured can yield corresponding interference surface patterns. Based on the interference rules of the two interference surface patterns, the beam angle between the two beams of light to be measured can be calculated.

[0092] like Figure 7 , Figure 8 As shown, step S220 further includes the following specific steps:

[0093] Step S221: Based on the two interference surface diagrams, calculate the beam deflection angle of each beam of the outgoing light to be measured.

[0094] Because laser interferometry is performed individually on each beam of light to be measured, multiple interference surface patterns are obtained. Based on the laws governing interference and deflection angles, the beam deflection angle of each beam of light to be measured can be determined from each interference surface pattern.

[0095] Step S222: Calculate the beam angle between the two beams of light to be measured based on the beam deflection angles of the two beams of light to be measured.

[0096] Once the beam deflection angles (angle values ​​and directions) of the emitted beams to be measured are detected, the beam angle between the two beams can be obtained directly through angle calculation.

[0097] The beam angle is compared with a preset angle value that meets the quality requirements. If the beam angle is less than the preset angle value, the prism structure is considered to meet the quality requirements and no angle correction is needed. However, if the beam angle is greater than or equal to the preset angle value, angle correction is required to ensure that the beam angle of the outgoing light after passing through the prism structure is less than the preset angle value, thereby ensuring that the prism structure meets the quality requirements.

[0098] like Figure 8 As shown, the specific steps of the angle correction process are as follows:

[0099] Step S300: Calculate the optical path difference between the two beams of light to be measured based on the angle between the beams and the direction of the deviation.

[0100] In the specific process described above, the angle and deflection direction of the beam can be obtained from the two interference surface diagrams. This beam angle arises because the reflecting surface (splitter) of the optical component in the optical path differs from the theoretical value. Thus, theoretically, the two beams of light to be measured with the same optical path will have different actual optical paths due to errors in the actual optical components. Therefore, based on the detected beam angle, the optical path difference between the two beams of light to be measured in the optical path can be calculated.

[0101] Step S310: Based on the optical path difference between the two beams of light to be measured, obtain the angle value and direction of the combined deflection angle generated by all reflection processes in the optical path of the prism structure.

[0102] In practice, the actual optical paths of each beam within a prism structure will have certain deviations. This deviation is reflected by an angle, i.e., the overall deflection angle. For example, if the actual optical paths of each beam are the same and the optical path difference is 0, then the overall deflection angle is 0. However, due to prism quality issues causing optical path differences, there are overall deflection angles between the optical paths of the cemented prism. The overall deflection angle is composed of the reflection angle deviation of each individual prism component, thus reflecting the overall deviation between the optical paths of the entire prism structure. Based on the results of the laser interferometry detection process, the angle and direction of the beam angle between the two outgoing beams to be measured are obtained, thus representing the angle and direction of the overall deflection angle of the entire optical path. Typically, the overall deflection angle is reflected by detecting the beam angle between multiple outgoing beams to be measured.

[0103] Step S320: Adjust the angle of the reflecting surface in the prism structure according to the angle value and direction of the comprehensive deflection angle so that the beam angle between the two beams to be measured is less than the preset angle value.

[0104] In practice, the angle of a single prism can be adjusted based on the overall angle and direction of the optical path. For example, the angle of one or more reflecting surfaces (reflective surfaces) of each prism can be adjusted. This ensures that the angle between the two emitted beams being measured is less than a preset angle value, thus making the multiple emitted beams essentially parallel. For example, the preset angle value can range from 10″ to 20″, such as 15″.

[0105] In this embodiment, the reflection angle of the single-use part in the optical path of the corresponding outgoing light to be measured is corrected so that the beam angle between the two outgoing lights to be measured is less than a preset angle value; wherein the direction of the angle corrected by the single-use part is opposite to the direction of the comprehensive deflection angle, so as to cancel the angle deviation of the comprehensive deflection angle.

[0106] In conjunction with the structure in Embodiment 1, for example, in this beam splitter lens assembly, the single-use section includes a second beam-splitting surface and / or a third beam-splitting surface. If multiple second prisms are used, the second beam-splitting surfaces of the multiple second prisms are divided into single-use sections. For example, by correcting the angles of the multiple second beam-splitting surfaces, the emission angles of the lower first emitted light (beam splitter 2) and the lowest first emitted light (beam splitter 2) can be adjusted. And by adjusting the angle of the third beam-splitting surface, the upper first emitted light (beam splitter 1) can be adjusted. After adjusting the overall deflection angle of the beam splitter lens assembly, the parallelism between any two of the three emitted first emitted light beams is required to be less than 15″. Therefore, the single-angle error of each single-use section must be within 5″.

[0107] For example, in this cemented lens assembly, a single-use section includes the reflecting surface of a reflective waveplate and / or the reflecting surface of a pyramid. By correcting the angle of the reflecting surface of the reflective waveplate and / or the reflecting surface of the pyramid, the beam angle between the second emitted beams is changed. After adjusting the overall deflection angle of the cemented lens assembly, the parallelism between any two pairs of the three emitted second emitted beams is required to be less than 15″. Therefore, the single-angle error of each single-use section must be within 5″; otherwise, the angle error will be difficult to meet the target requirements due to the superposition of individual component errors in the detection system.

[0108] By detecting the beam angle between each pair of emitted beams, the optical path of the prism structure (cemented prism) with problems can be deduced, thereby correcting the defective prism components and ensuring that the beam angle of the emitted light in the entire optical path meets the standard, thus confirming that the quality of the prism structure (cemented prism) meets the standard.

[0109] Example 2

[0110] This application also proposes a device for detecting the beam angle of a cemented prism, wherein the angle detection and correction method described above is applied. The detection device includes a laser interferometer and a data processor. The laser interferometer emits a detection beam toward the prism structure to acquire at least two beams of light to be measured emitted from the prism structure and performs laser interference on them respectively. The data processor calculates and obtains the beam angle between the at least two beams of light to be measured.

[0111] A laser interferometer can be used to detect the beam angles between pairs of parallel beams from a prism structure (cemented prism). The accuracy of parallelism measurement using a laser interferometer can reach within 1″, and it avoids mutual interference between multiple beams. This simple and convenient method of directly measuring parallelism using a laser interferometer is sufficient to detect the beam angles between pairs of parallel outgoing beams from a cemented prism.

[0112] In summary, this application provides a method and apparatus for detecting and correcting the angle between multiple outgoing beams of a prism structure. A laser interferometer can quickly and accurately measure the parallelism between pairs of outgoing beams from a cemented prism. Furthermore, the laser interferometer can provide the direction of deflection of the outgoing beams, thereby obtaining the overall deflection angle of the cemented prism. This allows for control of the angle of individual prisms during the optical bonding process. By changing the angle of an individual prism, the angle correction can be complementary within the optical path of the beam in which the corrected prism participates, thus offsetting the accumulation of errors.

[0113] The above embodiments are only used to illustrate the technical solutions of this disclosure, and are not intended to limit it. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this disclosure, and should all be included within the protection scope of this disclosure.

Claims

1. A method for detecting and correcting the included angle of a plurality of exit beams of a prism structure, characterized in that, The included angle detection correction method comprises the steps of: emitting a detection light beam towards the prism structure, and obtaining at least two beams of to-be-detected emergent light emitted from the prism structure; based on a laser interference principle, performing laser interference on the at least two beams of to-be-detected emergent light respectively, and obtaining a light beam included angle between the at least two beams of to-be-detected emergent light; calculating, according to an angle and a deflection direction of the light beam included angle between the two beams of to-be-detected emergent light, an optical path difference between light paths of the two beams of to-be-detected emergent light; obtaining, according to the optical path difference between the light paths of the two beams of to-be-detected emergent light, an angle value and a direction of a comprehensive deflection angle generated by all reflection processes in the light path of the prism structure; the prism structure comprises a common part and a single-use part for reflection of the light beam, wherein the common part is shared by the light path of the at least two beams of light, and the single-use part is used exclusively for the light path of each beam of laser light; by correcting the reflection angle of the single-use part in the light path of the corresponding to-be-detected emergent light, the light beam included angle between the two beams of to-be-detected emergent light is less than a preset angle value; wherein the direction of the corrected angle of the single-use part is opposite to the direction of the comprehensive deflection angle, so as to offset the angle deviation of the comprehensive deflection angle.

2. The method for the included angle detection correction of the multi-exit light beams of the prism structure according to claim 1, characterized in that, based on a laser interference principle, performing laser interference on the at least two beams of to-be-detected emergent light respectively, and obtaining a light beam included angle between the at least two beams of to-be-detected emergent light comprises the steps of: performing laser interference on the at least two beams of to-be-detected emergent light respectively, and obtaining at least two corresponding interference surface shape maps; according to the two interference surface shape maps, obtaining the light beam included angle between the two beams of to-be-detected emergent light.

3. The method for the included angle detection correction of the multi-exit light beams of the prism structure according to claim 2, characterized in that, in the step of obtaining the light beam included angle between the two beams of to-be-detected emergent light according to the at least two interference surface shape maps: according to the two interference surface shape maps, calculating the light beam deflection angle of each beam of to-be-detected emergent light respectively; according to the light beam deflection angles of the two beams of to-be-detected emergent light, calculating the light beam included angle between the two beams of to-be-detected emergent light.

4. The method for the included angle detection correction of the multi-exit light beams of the prism structure according to claim 1, characterized in that, in the step of emitting a detection light beam towards the prism structure, and obtaining at least two beams of to-be-detected emergent light emitted from the prism structure: the prism structure comprises: a beam splitter mirror group for splitting a beam of detection laser, thereby emitting a plurality of first emergent light; wherein the beam of detection laser serves as a detection light beam, and the first emergent light serves as to-be-detected emergent light; or / and a cemented mirror group for emitting a plurality of second emergent light by propagating a plurality of the detection incident light beams in different positions in the cemented mirror group along predetermined light paths; wherein the plurality of detection incident light beams are detection light beams, and the second emergent light corresponding to the plurality of detection incident light beams is to-be-detected emergent light.

5. The method for the included angle detection correction of the multi-exit light beams of the prism structure according to claim 4, characterized in that, in the step of emitting a detection light beam towards the prism structure, and obtaining at least two beams of to-be-detected emergent light emitted from the prism structure: The beam splitter mirror group and the cemented mirror group constitute a cemented prism, the multiple beams of first emergent light emitted from the beam splitter mirror group are multiple beams of detection incident light of the cemented mirror group, one beam of detection laser is split by the beam splitter mirror group to form multiple beams of first emergent light; multiple beams of the first emergent light propagate along predetermined light paths at different positions in the cemented mirror group and are respectively emitted to form multiple beams of the second emergent light.

6. The method for the included angle detection correction of the multi-exit light beams of the prism structure according to claim 5, characterized in that, In the step of correcting the reflection angle of the single-use part in the light path where the corresponding to-be-measured emergent light is located, so that the beam included angle between the two beams of to-be-measured emergent light is less than a preset angle value: The beam splitter mirror group comprises: A first polarization beam splitter prism, the first polarization beam splitter prism has a first light entrance surface and a first polarization beam splitting surface; At least one second prism, the second prism is connected to the first polarization beam splitter prism and has a first light splitting surface, a second light splitting surface and a first light exit surface; A third prism, the third prism is connected to the first light splitting surface of the second prism and has a third light splitting surface and a second light exit surface, the second light exit surface is arranged on the same side as the first light exit surface; The detection laser is incident from the first light entrance surface, reflected by the first polarization beam splitting surface, split by the first light splitting surface to form two beams of light, one of which penetrates through the first light splitting surface into the third prism, is reflected by the third light splitting surface and emitted from the second light exit surface to form one beam of the first emergent light; the other beam of light is reflected by the first light splitting surface, reflected again by the second light splitting surface and emitted from the first light exit surface to form another beam of the first emergent light; The single-use part of the beam splitter mirror group includes the second light splitting surface and / or the third light splitting surface, and the angle of the second light splitting surface and / or the third light splitting surface is corrected so that the beam included angle between the first emergent light is less than a preset angle value.

7. The method for the included angle detection correction of the multi-exit light beams of the prism structure according to claim 5, characterized in that, In the step of correcting the reflection angle of the single-use part in the light path where the corresponding to-be-measured emergent light is located, so that the beam included angle between the two beams of to-be-measured emergent light is less than a preset angle value: The cemented mirror group comprises: A second polarization beam splitter prism, the second polarization beam splitter prism has a second light entrance and exit surface, a second polarization beam splitting surface, and a first side surface and a second side surface arranged opposite each other; At least two reflection combination mirrors, the reflection combination mirrors are respectively arranged at different positions of the second polarization beam splitter prism and correspond to different first emergent light respectively, wherein the reflection combination mirror comprises a reflection wave plate and a corner cube, and the reflection wave plate and the corner cube are respectively arranged on the first side surface and the second side surface; The first emergent light enters the second polarization beam splitter prism through the second light entrance and exit surface, is reflected by the second polarization beam splitting surface to the reflection wave plate, penetrates through the second polarization beam splitting surface after being reflected by the reflection wave plate to enter the corner cube, enters the reflection wave plate after being reflected by the corner cube on both sides to penetrate through the second polarization beam splitting surface, is reflected by the reflection wave plate after entering the second polarization beam splitter prism to be reflected by the second polarization beam splitting surface, and is emitted from the second light entrance and exit surface to form the second emergent light. The single-use part of the glued mirror group comprises a reflecting surface of a reflecting wave plate and / or a reflecting surface of a corner cube, and the reflecting surface of the reflecting wave plate and / or the reflecting surface of the corner cube are angle-corrected so that the included angle between the second emergent lights is less than a preset angle value.

8. A device for detecting the angle of a glued prism light beam, characterized in that, The included angle detection and correction method as claimed in any one of claims 1-7 is applied, the detection device comprises a laser interferometer and a data processor, the detection device emits a detection light beam towards the prism structure through the laser interferometer, acquires at least two emergent lights to be detected from the prism structure and respectively performs laser interference, and the data processor performs calculation to acquire the included angle between the at least two emergent lights to be detected.

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